I used to be able to keep about 20 hives in a typical farm location of soybeans, alfalfa and corn without any noticable loss in production. With "roundup-ready" crops, that number has fallen in recent years to more like 10. The farmers are killing every weed in the fields now... in my good locations, where the farmer lets the alfalfa bloom and doesn't spray the soybeans for aphids, It's more like 30 or more.

.It has been researched that if you put hives in one punch, they tend to use to fly to nearest flowers and behind 800 m on canola field pollination effect is not seen. So researchers recommended that hives are in different sites around the field and pollination is better. And ofcourse bees get quickly full load compared to rush field.

Another thing more. In Austarlia researchers recommend one hive per 2 hectares canola. In Canada they recommend 4 hives per hectare. Actually the latter number is for pollination F1 hybrid seeds, not for honey production.

This is a real mesh in litterature. It is better to find out your self what is a right number.

In Finland recommendation is 2 hives per hectare. So when I have 50 hectares canola, I can put there 100 hives. That is merely ridiculous.

Last summer I had 50 hectares canola and 3 hives. I got almost nothing there because did not give honey last summer. So it is disaster to play with one card or "put eggs in same basket".

What ever plant yield may fail because of weathers. That is why it is better to situate hives on different kind pastures.